Monitoring blood glucose level through non-invasive methods has been very attractive to diabetic patients, scientific community and commercial establishment. Although the feasibility of near infrared (NIR) spectroscopy for non-invasive measurement has been demonstrated by many researchers since late 1970's, improving the reliability of measurement and analysis methods have been the main focus of research and development. Almost all of these measurement techniques either uses bulky and powerful arc/halogen larnps with acousto-optic tunable filters or big tunable lasers to obtain transmission /absorption spectrum of the tissue which will then be used to estimate blood glucose level. No matter what reliable method is used in determining the glucose level, the commercial success of a non- invasive glucose monitoring system will depend on the cost and size of the system. Building on its already proven technology, CoreTek now proposes to develop a mass-producible compact micro-external-cavity laser diode operating at wavelength regions of glucose monitoring systems. The main goal of the this Phase I SBIR proposal is to develop a low-cost, compact tunable laser diode technology that will replace the bulky and costly light sources used for non-invasive glucose monitoring systems. PROPOSED COMMERCIAL APPLICATIONS: chemical & biomedical sample analysis fiberoptic communication